Some prime number stuff

#!/usr/bin/python -OOimport randomimport arrayimport mathdef make_prime(min_digits=100, max_digits=None):    if max_digits is None:        max_digits = min_digits + 1    while True:        i = random.randrange(10 ** min_digits, 10 ** max_digits)        if miller_rabin(i):            return i# 20 iterations gives us a 9.09e-11% chance of a strong liardef miller_rabin(cand, tests=20):    if cand is 2:        return True    #No even numbers allowed    if cand < 2 or not cand & 1:        return False    d = n1 = cand - 1    # factor powers of two from d    while not d & 1:        d >>= 1            for i in xrange(tests):        a = random.randrange(0, cand - 2) + 1        t = d        y = mod_mul(a, t, cand)        while t != n1 and y not in (1, n1):            y = (y * y % cand)            t <<= 1                        if y != n1 and ~t & 1:           return False                return True         def mod_mul(base, power, mod):    r = 1    while power:        if power & 1:            r = (r * base % mod)        base = (base * base % mod)        power >>= 1            return rdef eratosthenes(max):    r = array.array('L', [0,0,1])        for i in xrange(2,max):        r.append(1)            # Skip 0, 1    e = enumerate(r)    e.next()    e.next()    for i,j in e:        if j:            for k in range(i<<1, max+1,i):                r[k] = 0    return [i for i,j in enumerate(r) if j]# pi(x) approximates the number of primes less than xdef pi(max):    return long(max / math.log(max - 1))if __name__ == '__main__':    for i in range(10): print make_prime()